The invention relates generally to an arrangement for processing photosensitive articles.
More particularly, the invention relates to an arrangement for developing photosensitive articles such as film and the like.
A known arrangement for developing photosensitive articles has a processing chamber which is provided with a fluid inlet and a fluid outlet. The inlet communicates with a pump which delivers heated processing fluid to the chamber. The fluid is discharged from the chamber via the outlet and is received by a container having a capacity which greatly exceeds the capacity of the chamber. The fluid is withdrawn from the container by the pump and is recirculated to the processing chamber.
A developing arrangement of this type is disclosed, for example, in the German Pat. No. 19 62 422. This arrangement operates with a volume of processing fluid which substantially exceeds that required to fill the processing chamber and to maintain fluid circulation. A large quantity of processing fluid is used in order to maintain the chemical activity of the processing fluid relatively constant over an extended period of time.
As mentioned earlier, the processing fluid is heated. In order to place the arrangement in condition for operation, the entire quantity of fluid must be heated to the operating temperature. To this end, the container is provided with a thermostatically regulated heating device. The thermostat for the heating device also controls a transporting device for conveying the photosensitive articles into the processing chamber and prevents the transporting device from starting until the fluid has reached its operating temperature.
The rated output of the heating device relative to the quantity of the processing fluid is such that, as a rule, the time required for the fluid to reach its operating temperature is considerable. The design of the electrical circuitry prevents the use of a heating device having a greater rated output, e.g., to accelerate the initial heating of the fluid. Consequently, the operating personnel normally switch on the heating device at the beginning of the working day and do not switch it off again until the end of the working day regardless of whether or not there are idle periods during which no processing takes place. On the one hand, heating of the fluid throughout the entire working day requires large amounts of energy. On the other hand, the fluid undergoes a substantial amount of oxidation when it is maintained at its operating temperature for the entire working day.